<!DOCTYPE html>
<html>
<head>
  <title>My theme-integrated sidebar</title>
  <style>
  #myElement {
    font: menu;
    font-size: 1.5em;
    font-weight: 500;
    padding: 1em;
    margin: 1em;
  }
  </style>
</head>
<body>
  <div id="myElement">This is an awesome themed element!</div>
  <script src="sidebar.js"></script>
</body>
</html>